Laparoscopic surgery is an increasingly popular form of surgery. In laparoscopic surgery, several small incisions are made in the patient's abdomen and a tube, or trocar, is inserted through each incision. All surgical instruments, including staple or clip applicators and extractors, are inserted through a trocar. Although surgical staple applicators are capable of holding and applying multiple staples during a single insertion through a trocar, surgical staple extractors, such as those disclosed in U.S. Pat. Nos. 4,487,394 and 4,026,520, are capable of retracting and holding only one staple at a time. Furthermore, the size of most conventional extractors prohibits their use during laparoscopic surgery as the devices are too large to be inserted through a trocar. Also, trocars provide limited mobility for the movement of many instruments. Thus, when removing staples or clips during laparoscopic surgery, it is very time consuming to repeatedly insert conventional staple extractors through the trocar, grasp a single staple, remove it through the trocar, and repeat the process for each staple. It is desirable to reduce the time needed for this process, as well as any other step during surgery, to reduce the risk of infection to the patient.
Another problem posed by laparoscopic surgery in the removal of surgical staples is the visualization of applied staples. U.S. Pat. Nos. 3,643,851, 3,717,294 and 3,837,555 disclose devices for the stapling of skin. The staple used with these devices comprises two straight edges joined by a crossbar. The surgical staple disclosed in U.S. Pat. No. 4,014,492 has a more complex shape prior to insertion that assists in the gathering of the skin during emplacement. All of these staples would be difficult to locate through a trocar as the staple, when inserted into the skin or tissue, is shaped such that the exposed portion of the staple lies directly on the surface of the skin or tissue.
Specialized stapling systems have been developed for particular applications other than laparoscopic surgery. The staple, method, and extractor disclosed in U.S. Pat. No. 4,434,796, for example, is used to join bone tissues. In this system, extraction of the staples is accomplished one staple at a time, and , in fact, requires multiple extraction efforts for the removal of one staple.